redactApiKey function
Redact an API key, showing only the first and last few characters.
Implementation
String redactApiKey(String key) {
if (key.length <= 8) return '*' * key.length;
final showChars = (key.length > 20) ? 4 : 2;
return '${key.substring(0, showChars)}${'*' * (key.length - showChars * 2)}${key.substring(key.length - showChars)}';
}